package com.dllo.lanou.cookapp.utils;

import android.view.View;
import android.view.ViewGroup;
import android.widget.ListAdapter;

import com.dllo.lanou.cookapp.view.MyListView;

/**
 * Created by xijinhua on 2016/4/2.
 */
public class ScrollViewUtil {
//理就是动态的改变ListView控件的高度。
    public static void setListViewHeightBasedOnChildren(MyListView listView) {
//获取ListView对应的Adapter
        ListAdapter listAdapter = listView.getAdapter();
        if (listAdapter == null) {
// pre-condition
            return;
        }

        int totalHeight = 0;
        for (int i = 0, len = listAdapter.getCount(); i < len; i++) { //listAdapter.getCount()返回数据项的数目
            View listItem = listAdapter.getView(i, null, listView);
            listItem.measure(0, 0); //计算子项View 的宽高
            totalHeight += listItem.getMeasuredHeight(); //统计所有子项的总高度
        }

        ViewGroup.LayoutParams params = listView.getLayoutParams();
        params.height = totalHeight + (listView.getDividerHeight() * (listAdapter.getCount() - 1));
//listView.getDividerHeight()获取子项间分隔符占用的高度
//params.height最后得到整个ListView完整显示需要的高度
        listView.setLayoutParams(params);
    }
}
